Dyeing Process Control Method Of Conveyor Drive Rope-Like Fabric Dyeing Machine

ABSTRACT

Disclosed is a method for controlling a dyeing process of a conveyor drive rope-like dyeing machine, which uses the number of cycles of circulation of fabric in a dyeing bath as a control unit for controlling the dyeing process. In other words, the entire dyeing process, including the speed of adding chemicals, the speed of heating/cooling, the time interval of holding temperature, and the time interval of rinsing with water, and the likes of the dyeing process, is controlled with the number of cycles of circulation of fabric as the control unit for a computer or a programmable logic controller to control the dyeing process.

(a) TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to a conveyor drive fabric dyeing machine that is used to dye rope-like fabric, and more particularly to a method for controlling a dyeing process.

(b) DESCRIPTION OF THE PRIOR ART

FIG. 1 is a schematic view illustrating a dyeing circulation of fabric in a conventional dyeing machine. The operation principle is that dye liquid F is pressurized by a pump D2 and passes through a heat exchanger C (for increasing or decreasing temperature) into a nozzle A4 to generate a jetting or overflowing liquid flow and then returns to a fabric accumulation tank A1 of a dyeing machine A. Fabric B is driven by a fabric roller A3 (or alternatively using no fabric roller) into the nozzle A4 so that the fabric B is driven by the force induced by the jetting or overflowing liquid flow from the nozzle A4 to circulate. Dye liquid and chemical agents are supplied from a service tank E and pressurized by a pump D1 to feed into a dyeing circulation loop of the dyeing machine A. During the circulation, the dye liquid F and the fabric B undergo a process of heating, temperature holding, and cooling achieved with the heat exchanger C to have the dye absorbed by the fabric thereby achieving a dyeing effect of scouring, coloring, color fixing, and water rinsing. Uniformity of dyeing (levelness) is determined by the number of cycles of circulation of the fabric during the dyeing process, namely the number of interactions between the fabric B and the dye liquid in the nozzle A4 and the dyeing tube A2. A great number of cycles of circulation indicates a great number of interactions and thus better uniformity of dyeing, as well as the extent of water rinsing and dyeing fastness.

Referring to FIG. 2, which shows a typical dyeing process employed in a conventional dyeing machine, theoretically or empirically, the conventional dyeing machine uses “time” as a control unit (denominator) to carry out treatments of fabrics dyeing, including, in sequence, chemicals adding, heating, temperature holding, heating, temperature holding, cooling, water rinsing, chemicals adding, heating, temperature holding, cooling, and hot water rinsing. Control is generally achieved with a computer or a programmable logic controller (PLC).

Since the conventional dyeing machine uses “time” as a control unit, it generally takes the same amount of time to complete a dyeing process regardless the actual length or weight of the fabrics being dyed. However, in an actual dyeing process, since different pieces of fabric that are dyed may have different weights or the thicknesses of the fabrics may be different, the lengths of fabrics in each batch and each tube may be different. Although the fabrics may be of the same type, adopting a dyeing process of the same amount of dyeing time is generally a waste of time. Further, during the entire dyeing process of the fabrics, due to the actual amount (length) of fabric to be dyed in each batch or each tube of the dyeing machine being different, the number of cycles of circulation is different. Consequently, even though the dyeing time is identical, the extent of dyeing so obtained is different, leading to issues regarding tube deviation or batch deviation, inconsistent dyeing fastness, and poor reproductivity. As such, re-dyeing may be necessary and the quality and efficiency of productions are poor. A great amount of energy and human labor are wasted and additional environmental pollution may result. Such a reproductivity issue is a long existing problem of the dyeing workshops and has not yet been overcome.

SUMMARY OF THE INVENTION

An object of the present invention is to overcome the problems occurring in a dyeing process of a conventional dyeing machine that uses “time” as a control unit so that the same amount of time is taken in carrying out the dyeing process for the same type of fabrics regardless the actual lengths of the fabrics that are dyed so that even though the dyeing time is identical, the results of the dyeing operations are different thereby leading to the problems of batch deviation or tube deviation, inconsistent fastness, poor reproductivity, and waste of time.

To overcome such problems, the present invention is made to change the way of control of the conventional dyeing machine by using the number of cycles of circulation of fabric as a control unit (denominator). In other words, the horizontal axis of the plot shown in FIG. 2 is changed from “time” to “number of cycles of circulation of fabric”. As such, regardless the actual length of fabric introduced, the dyeing process is controlled on the basis of the number of cycles of circulation of fabric. For a rope of fabric having a great length, the time required for the entire dyeing process is long; and for a rope of fabric having a small length, the time required for the entire dyeing process is short. Thus, since, for fabrics of the same type, the number of cycles of circulation adopted for each dyeing tube or each batch of the dyeing operations of the fabrics is all the same, the degree of dyeing and the extent of water rinsing are all identical. This ensures zero tube deviation or zero batch deviation, consistent fastness, and one hundred percent of reproductivity and greatly improves the quality and efficiency of production and also greatly reduces the dyeing cost and achieves environmental protection through saving energy and reducing carbon.

The technical solution of the present invention is to arrange a fabric seam and circulation time and circulation cycle counter at a proper location in a machine body of a conveyor chive rope-like fabric dyeing machine. Since movement of fabric from a rear end toward a front end is driven by a conveyor, a circulation speed of the fabric is synchronous with the conveyor. Thus, although circulation time of the fabric of each cycle of circulation is adjustable, a fixed speed and a fixed time period are adopted once selected and set. The present invention makes use of such a characteristic of speed being fixed and, through employment of a computer of a programmable logic controller (PLC), uses the number of cycles of circulation of fabric as a control unit for the dyeing process. This ensures, as mentioned above, shortening of dyeing time, no color deviation, no batch deviation, consistent fastness, and one hundred percent of reproductivity, and also improve product quality, improves production efficiency, lowers down manufacturing cost, saves energy and reduce carbon, and enhances environmental protection.

The advantages of the present invention includes:

-   -   (1) The time of an entire dyeing process can be shortened         according to the length of a rope of fabric that is dyed.     -   (2) Regardless the actual lengths of the fabrics dyed, the         number of cycles of circulation is made identical so that the         interaction degree of dyeing is identical and the reproductivity         of dyeing is one hundred percent and there is no tube deviation         and no batch deviation, and no concern about fastness         difference.     -   (3) Regardless the actual lengths of the fabrics dyed, the         number of cycles of circulation is the same and the number of         contacts between a fabric and the dyeing machine (friction and         stretching) is the same, so that the quality of the fabric is         consistent.

The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a cycle of circulation of dyeing fabric in a conventional dyeing machine.

FIG. 2 is a plot showing a typical dyeing process of the conventional dyeing machine.

FIG. 3 is a plot showing a dyeing process of a conveyor drive rope-like fabric dyeing machine according to the present invention.

FIG. 4 is a schematic view showing the conveyor drive rope-like fabric dyeing machine according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

As shown in FIG. 4, the present invention provides a conveyor drive rope-like fabric dyeing machine, which comprises a fabric seam and circulation time and circulation cycle counter arranged at a proper location in a machine body of the conveyor drive rope-like fabric dyeing machine. Since movement of fabric from a rear end toward a front end is driven by a conveyor, a circulation speed of the fabric is synchronous with the conveyor. Thus, although circulation time of the fabric of each cycle of circulation is adjustable, a fixed speed and a fixed time period are adopted once selected and set. The present invention makes use of such a characteristic of speed being fixed and, through employment of a computer of a programmable logic controller (PLC), uses the number of cycles of circulation of fabric as a control unit for the dyeing process. This ensures, as mentioned above, shortening of dyeing time, no color deviation, no batch deviation, consistent fastness, and one hundred percent of reproductivity, and also improve product quality, improves production efficiency, lowers down manufacturing cost, saves energy and reduce carbon, and enhances environmental protection.

FIG. 3 is a plot showing a dyeing process of a conveyor drive rope-like fabric dyeing machine according to the present invention, in which “number of cycles of circulation” is used to substitute “time” that is used as the horizontal axis of the dyeing curve shown in FIG. 2 of a conventional rope-like fabric dyeing machine and a computer or a programmable logic controller is used to control the dyeing process. In other words, treatments of the dyeing process, including, in sequence, chemicals adding, heating, temperature holding, heating, temperature holding, cooling, water rinsing, chemicals adding, heating, temperature holding, cooling, and hot water rinsing are carried out with the “number of cycles of circulation” being taken as a control unit. This means the amount of chemical added each time, the temperature variation achieved in each heating or cooling operation, the temperature interval of temperature holding or water rinsing, and the likes are all controlled with the “number of cycles of circulation” as the control unit. In this way, the total time for a dying process may differ for different lengths of a piece of fabric subjected to the dyeing process. For example, for the same type of fabric, a 500 kg capacity dyeing machine that, in actual operations, would spend about half the time used for handling fabric of 500 kg in handling fabric of 250 kg, but provide exactly the same degree of dyeing and the same result of dyeing thereby achieving consistent reproductivity. This is a revolutionary innovation.

It can be appreciated from the above description that the actual dyeing effect obtained with the conveyor drive rope-like fabric dyeing machine is primarily and directly determined by the number of cycles of circulation of the fabric, not the length of time (namely an absolute relationship being had with respect to the number of cycles of circulation, while a relative relationship is had with respect to time). Thus, when the fabric speed in each tube or each batch of the dyeing machine is the same, if the time used is the same, then the number of cycles of circulation is less for fabric having a greater length and the number of cycles of circulation is greater for fabric having a shorter length. Thus, even though time is the same, the degree of dyeing is different and the result of dyeing is also different, leading to issues of tube deviation, batch deviation, inconsistent fastness, and inconsistent reproductivity. Thus, to have consistent result of dyeing for fabrics of the same type, the number of cycles of circulation must be identical regardless the actual length of fabric dyed. In other words, for fabric that is short, the time can be shortened correspondingly. This can shorten the time for the entire dyeing operation and since the number of cycles of circulation is the same regardless the length of the fabric, the degree of dyeing is the same and one hundred percent of reproductivity of dyeing can be achieved. Thus, there will be no need for re-dyeing due to tube deviation or batch deviation and inconsistency of fastness.

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. 

I claim:
 1. A method for controlling a dyeing process of conveyor drive rope-like fabric dyeing machine, in which time interval or speed of treatments of chemical addition, heating, temperature holding, cooling, and water rinsing of the dyeing process are controlled with number of cycles of circulation of fabric in the dyeing machine as a control unit in carrying out dyeing of the fabric. 